Cytokines regulating acute inflammation and synthesis of acute phase proteins.

The acute phase response to injury includes metabolic alterations, such as fever, leucocytosis, enhanced uptake of some metals and amino acids by liver, and changes in the synthesis of certain plasma proteins. Many of these effects can be elicited either in vivo or in tissue culture by monocyte- and keratinocyte-derived cytokine interleukin 1 (IL-1), which had earlier been variably termed leucocytic endogenous mediator, lymphocyte activating factor, or endogenous pyrogen. Although recombinant murine IL-1 was shown to induce hepatic synthesis of acute phase proteins other authors demonstrated that hepatocyte stimulating factor (HSF) is distinct from IL-1. Possible relationships between HSF und IL-1 and the molecular mechanisms of action of these cytokines on the synthesis of acute phase proteins are briefly discussed.